The prior art is already aware of tool holders, including adapters, which are arranged for radially stabilizing replaceable and rotatable tools. Further, there are holders which utilize two axially spaced apart and spring urged balls for the stabilizing effect. In those occurrences, the springs and other members urging the balls into holding positions are arranged to have the spaced apart balls or the like under the influence of the same urging such that the holding balls act only in unison and not independent of each other. Thereby, the holding effort on the tool is limited to that one holding action with both balls moving only in unison and not adapting to independent ball movement and holding of the tool, and thus the holding action is limited in its precision.
The present invention improves upon the prior art in that it is precise in holding the various tools which are inserted into the holder. Those tools themselves may be imprecise in their configuration and therefore difficult to hold in radial and axial, accuracy, and this invention avoids those problems. Both radial and axial play are avoided.
Further, this invention can be reduced to an actual construction which produces a precise, efficient, and relatively inexpensive construction. There is optimum precision in the holding feature to thereby avoid radial play or movement of the tool relative to the holder itself. In this construction, there is achieved two separate and independent radial holdings, and only one motion is required to release the two holdings. So it is possible that the holder of this invention has the exterior shaping of that of the prior art and it is also operated the same as that of the prior art, so no new and different familiarizing by the user is required.